I think Portablizing discord is straight forward once it's realized (a) it must be run-as-spot and (b) although discord is based on electron --the same as Chrome and Chomium-- much of the work mikewalsh's did portablizing Google-Chrome was not necessary to run discord.
Caution: I don't have a discord account so don't know if the portable is fully functional. All I do know is that it opens.
Download the deb from here, https://discord.com/download
Download discord-portable64.tar.gz.
Right-Click the tar.gz and select either pExtract or UExtract from the pop-up Menu. Extract. This generates an discord-portable64 folder (which may be within a discord-portable64-Extracted folder). Move the discord-portable64 folder onto any partition. It can be in a subfolder. [Only /mnt/home is mounted on boot-up by default].
Extract the discord.deb. Within the extracted folder you'll find a /usr/share/discord folder. Move that entire folder into your discord-portable64 folder. The contents of that folder should now look like the following screenshot. You can start discord by Left-clicking the LAUNCH script. Menu-Add will create menu entries under Internet and Network. Menu-Remove will remove them.